Method and apparatus for knitting run-resistant fabric



March 4, 1969 NEBELH ETAL 3,430,452

METHOD AND APPARATUS FOR KNITTING RUN-RESISTANT FABRIC Filed March 31,1967 Sheet of 5 '1 a n r l HQ I i s} P h 2 N1 N2 IFF N2 N1 N x FIG. 3

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BY ERHARD MAX NEBEL @JI M ATTORNEYS MAX BRUNO NEBEL Mar h 4, 1969 M. B.NEBEL ETAL 3 430 4 2 METHOD AND APPARATUS FOR KNITTING RUN-RESISTANTFABRIC Sheet Filed March 31, 1967 Elly.

omwm 2m PwmE Qwwm zm 0200mm INVENTOR. MAX BRUNO NEBEL BY ERHARD MAXNEBEL ATTORNEYS.

March 4, 1969 BI NEBEL ET L METHOD AND APPARATUS FOR KNITTINGRUN-RESISTANT FABRIC Sheet Filed March 31, 1967 JNVENTOR.

MAX BRUNO NEBEL I By ERHARD MAX NEBEL F! v M ATTO R N EYS United StatesPatent 3,430,462 METHOD AND APPARATUS FOR KNITTING RUN-RESISTANT FABRICMax Bruno Nebel and Erhard Max Nebel, Wiesbaden,

Germany, assignors to Hanes Corporation, a corporation of North CarolinaDivision and continuation-in-part of application Ser. No. 347,735, Feb.27, 1964, now Patent No. 3,319,440, dated May 16, 1967. This applicationMar. 31, 1967, Ser. No. 627,350 US. Cl. 66-42 22 Claims Int. Cl. D04b15/80, 9/38 ABSTRACT OF THE DISCLOSURE Method and apparatus for knittingrun-resistant fabric from at least two yarns, which alternate walewiseof the fabric, and in which one yarn is formed into alternate plainstitches in selected wales and into floats in the intervening wales, andin which the next succeeding yarn is formed into plain stitches in theintervening wales and into elongated loops in the selected wales, withthe elongated loops being doubled with the next succeeding plainstitches in the selected wales throughout the fabric.

This application comprises a division and a continuation-in-part of U.8. Patent No. 3,319,440, granted May 16, 1967.

The primary object of this invention is to provide new and usefulmethods and apparatus for producing new and useful run-resistant knittedfabrics, for use in ladies sheer hosiery and the like.

Another object is to provide a novel method of producing suchrun-resistant fabric on a conventional multifeed circular knittingmachine.

A further object is to provide new and improved apparatus for producingsuch circular knit fabric on a knitting machine having two separate yarnfeeds, or multiples thereof.

Other objects of this invention will become apparent when the followingdescription thereof is read with reference to the accompanying drawingsin which:

FIG. 1 illustrates diagrammatically the inside of a preferred form ofthe run-resistant fabric of this invention;

FIG. 2 comprises a development of the camming for a two feed circularknitting machine for making the fabric of FIG. 1;

FIGS. 2a, 2b, 2c, 2d and 2x are enlarged fragmentary views in sideelevation illustrating the operating positions of the needles andsinkers at diiferent steps of the method of the invention;

FIG. 3 is an enlarged fragmentary schematic view, taken from the insideof the needle cylinder, showing the needles and sinkers of the machineat one of the yarn feeds thereof;

FIG. 4 is a fragmentary schematic view in top plan showing the sinkercams and the relative positions of the sinkers of the machine; and

FIG. 5 is a fragmentary view in elevation showing a preferred type ofneedle used in the practice of this invention.

The run-resistant fabric shown diagrammatically in FIG. 1 is knit ofyarns a and b which alternate walewise of the fabric. Yarn a is formedinto alternate plain stitches A and elongated loops S, while yarn b isformed into plain stitches B alternating with floats H. In eachinstance, the yarn a is succeeded Wale-wise immediately by yarn b in thefabric, so that the plain stitches B of yarn b anchor the plain stitchesA of the preceding yarn a. By reason of this construction, each courseof the fabric may be said to consist of the two yarns a and b.

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Preferably, the plain knit stitches A of each pair of adjacent orsuccessive course-Wise extending yarns a are staggered Wale-wise of thefabric by one wale. Thus, the lowermost yarn a of FIG. 1 is formed intoelongated loops S in wales 1 and into plain knit stitches A in Wales 2,whereas the next succeeding yarn a is formed into elongated loops S inwales 2 and into plain k-nit stitches A in Wales 1. As a result of thisarrangement, the elongated loops S of each yarn a are doubled with theplain knit stitches A of the next succeeding yarn a in the fabric. Thus,stitches B actually anchor the double stitiches SA throughout thefabric.

Similarly, the plain knit stitches B and floats H of each yarn b arestaggered Wale-wise with respect to the stitches B and floats H of thenext successive or adjacent yarn b in the fabric Preferably the floats Hare bound into the fabric by the elongated loops S.

If it is considered that each course-wise extending yarn of the fabricof FIG. 1 comprises a separate fabric course, then it will be seen thatthe pattern repeat of the fabric is two needle wales in width and fourcourses in length.

In the preferred construction of the fabric, yarn a is of a longerlength per fabric course than yarn b, but of smaller denier. Forexample, a highly run-resistant fabric of the character shown in FIG. 1,having the appearance of plain knit fabric, is produced when yarn a has,per course, twice or more than twice the length of yarn b per course,and has one-half the denier of yarn b.

The fabric of FIG. 1, having a longer length of yarn a per course thanyarn b, is highly resistant to runs even when subjected to substantialwidth-wise or length-wise stress. In such situation, runs are deterredwhen a yarn is broken, for all practical purposes in the normal use ofthe fabric, because withdrawal of the double stitches SA, from plainstitches B is precluded.

FIGS. 2-4 illustrate the best mode presently contemplated for carryingout this invention. While, for purposes of illustration, the hereindescribed method and apparatus illustrate the invention as practiced ona two-feed circular knitting machine, it is to be understood that theinvention may be practiced on circular knitting machines havingmultiples of two yarn feeds, i.e., 4, 6, 8, etc. yarn feeding stations.

The needles of the machine preferably are divided into two groups,designated N and N which alternate in a l x 1 relationship around theneedle circle. Needles N are formed with the usual needle butts N, andmay also have auxiliary butts N (FIG. 3). Needles N are formed with theusual butts N, and, in addition, may also be formed with auxiliary buttsN Referring now to FIG. 2, it will be seen that the needles, duringtheir stitch formation action, move counterclockwise in the rotativedirection R. As the needles approach the first or main yarn feed of themachine, to take yarn a, they are divided alternatively by conventionalneedle selection means into the two needle groups N and N with needles Nraised to clear level, i.e., latch clearing level, and needles Ndisposed at tuck level E (FIG. 2x). More particularly, the needles N andN are selected by needle jacks T under the influence of reader cams O orO in the usual manner.

As needles N approach the first yarn feed, at clear level, they havestitches B of the yarn b on their shanks or stems below their latches Z.Needles N at tuck level E, have elongated yarn loops S of yarn a ontheir open and downwardly extending latches Z and have floats H, of thenext succeeding yarn b to the said yarn a, and stitches B, of the nextpreceding yarn b to the said yarn a (FIG. 1), onthe needle shanks belowtheir latches Z (FIG. 2x). The stitches B on needles N and the floats Hon needles N are formed from the same course-Wise extending yarn b inthe fabric.

While the needles approach the first yarn feed, the sinkers P areadvanced into the needle circle by the cam surfaces P and P of sinkercam P (FIG. 4). As a result, at the first yarn feed, yarn a is drawnover the sinker nebs P by needles N to form stitches A (FIGS. 2a, 3),while yarn a is laid over the latches Z of needles N and over the sinkernebs P to form elongated yarn loops S.

The first yarn feed is provided with two vertically spaced run-down camsC and C (FIG. 2). Cams C and C are spaced from each other to providetherebetween a needle butt track corresponding in width to the width ofthe needle butts N and N The conventional reverse stitch cam C and topcenter cam C are retracted from the needle circle and renderedinoperative.

Yarn a is delivered into the hooks of the needles N and N and thenneedles N are drawn down by run-down stitch cam C to form stitches A andcast off the floats H and the stitches B (FIG. 2a). Since elongatedloops S are still in the hooks of needles N they are doubled with thenewly formed stitches A to form double loops SA.

Needles N meanwhile, with the newly formed yarn loops S on their openlatches, are drawn down by cam C to a depth intermediate of tuck level Eand yarn cast off level (FIG. 2a). As a result, stitches B remain on theshanks of the needles N below their latches Z, while the newly formedloops S remain on and above the needle latches. The retention of loops Son the needle latches and separate from loops B on the shanks of needlesN is aided by the retention of the sinker nebs P within the needlecircle (FIG. 4).

After stitches A have been drawn by needles N the sinkers P are furtherinserted into the needle circle by cam surface P of sinker cam P (FIG.4). Sinker cam surfaces P and P serve as knockover cams, and aid incasting floats H and stitches B off of needles N during the formation ofthe new stitches A from yarn a. Sinker cam surfaces P and P advance thesinkers P sufliciently far into the needle circle to position the yarndrawing ledges P behind the sinker nebs P below the hooks of the needlesN After passing stitch cams C and C all needles N and N are raised totuck level E. Thereupon, all needles are raised to low clear level bycam C As a result, the double thread stitches SA are cleared from thelatches onto the stems of needles N However, because the sinker nebs Pstill penetrate the needle circle, the thread loops S are retained onthe latches Z of needles N Preferably, at this time, the sinkers P areretracted slightly by sinker cam P (FIGS. 2b, 4), so that the highestpoint of the sinker nebs P is positioned below the loops S on needles Nand above stitches B on needles N and double stitches SA on needles N Asan alternative, cam C may be omitted and the sinkers not retracted, butallowed to remain as positioned by cam surface Ps. In such case, needlesN only are raised, independently of needles N by their jacks T under theinfluence of reader cams O or 0 (see broken lines in FIG. 2), to latchclearing level. Consequently, the double stitches SA slip off thelatches Z onto the shanks of the needles N As the needles continue theirmovement in direction R, they are drawn down by cam C to or slightlybelow tuck level E. Thereafter, needles N are raised to low clear level,by needle jacks T under the influence of reader cam O or 0 However, thethread loops S are retained onthe latches of needles N by the sinkernebs P, which remain within the needle circle (FIG. 4). Needles Nmeanwhile, remain at or slightly below tuck level E. In these respectivepositions, the needles N and N advance toward the cams C and C whiletaking yarn b at the second yarn feed.

Needles N take yarn b in their hooks and are drawn down by the run-downstitch cam C to form new stitches B and cast off double stitches SA. CamC is spaced sufiiciently far in advance of cam C to draw needles N downto yarn cast off level before needles N reach cam C 4 As a result,needles N cause the yarn b to be laid below the latches Z against theshanks of the needles N (FIG. 20) to form floats H.

Needles N retain the yarn floats H under tension against the shanks ofneedles N until the latter needles have descended sufliciently toenclose the yarn floats H between their latches and shanks. To aidneedles N in this function, cam C preferably is formed with a flatbottom of a length suflicient to retain at least three needles N at anymoment, at cast off level.

More particularly, cam C retains needles N at cast ofl. level untilafter needles N have passed over cam C advanced to cam C and are causedto descend to tuck level E by the latter cam. This downward movement ofneedles N ensures the proper positioning of the floats H of yarn bbetween the latches and shanks 0f the needles N After cam C has loweredneedles N to tuck level E, needles N are raised to tuck level E. At thisstage of the process, needles N have yarn loops S on their latches andfloats H and stitches B below their latches on their shanks, whileneedles N have new stitches B on their latches. The floats H on theshanks of needles N and the new stitches B on the latches of needles Nare formed from the same course-wise extending yarn b, whereas thestitches B on the shanks of needles N are formed from the immediatelypreceding course-wise extending yarn b (see FIG. 1).

As the needles N take and draw yarn b, the sinkers P are positioned inrespect of the needle circle so that stitches B are drawn by needles Nover the yarn sinking ledges P behind the nebs P (FIGS. 20, 4). Toaccomplish this, sinkers P either remain in the position to which theyhad been advanced by cam surfaces P and P or, if they had been retractedslightly by cam P they are readvanced under the influence of sinkerspring N.

Sinker cam P (FIG. 4) serves as the knockover cam for the second yarnfeed. It advances the sinkers P further into the needle circle to aid incasting olf double stitches SA from needles N Because stitches B of yarnb are drawn over sinking ledges P of sinkers P, and stitches A of yarn aare drawn over the sinker nebs P yarn or will have a longer length percourse of the fabric than yarn b. Of course, even if the two yarns weredrawn over yarn sinking ledges at the same level, yarn a inherently willhave a longer yarn length per course than yarn b, since the lattercontains the floats H, whereas the former contains the inherently longerloops S.

Specially designed sinkers P are employed to carry out the method of theinvention. The sinkers are formed with a rearwardly extending edgepassing first downwardly from the top of the neb P to the sinking ledgeP and thence upwardly to a point spaced from the neb, as best shown inFIG. 2a. Sinking ledge P is the lowest portion of this rearwardlyextending edge, and is disposed somewhat lower than sinker throat P. Thevertical distance between the uppermost point of sinker neb P and theyarn sinking ledge P may be selectively designed to control the relativelengths per course of the yarns a and b. Preferably, the distance fromthe sinker throat P to the sinking ledge P should not exceed the widthof the hooks of the needles N N In order to facilitate the usual brokenneedle detector V (FIG. 2d), all needles N and N are drawn below tucklevel E a small distance by cam C Preferably, the needles are drawn downto position their hooks proximate the sinker nebs P, so that the floatsH and stitches B on needles N close the latches Z, but do not cast off.At this time, the sinkers P may be retracted by sinker cam P to positionall yarn loops on the needles below the nebs P (see broken lines in FIG.2d). Thereafter, all needles N and N are again raised to tuck level Ewhile proceeding in the rotative direction R to the next yarn feedwhich, in the embodiment shown, is the main or first yarn feed of themachine.

Before the needles again take yarn, they are selected to interchangetheir previously described action. More particularly, needles N now areraised to clear level (FIG. 2x) to transfer their stitches B onto theneedle shanks, while the needles N remain at tuck level E. Needles N nowhave elongated loops S on their open latches and floats H and stitches Bon their shanks below their latches. Meanwhile, the sinkers P have beenretracted from the needle circle, by either of sinker cams P or P", andthereafter are re-advanced into the needle circle by cam surfaces P andP to permit yarn a to be drawn over the sinker nebs, as previouslydescribed.

It is advantageous to reinsert the sinker nebs P into the needle circlegradually, first by cam surface P and thereafter, to a further extent,by cam surface P This arrangement will ensure that the tips of thesinker nebs will not re-engage the loops S on the needles, but will passabove those loops, as yarn a is drawn into the stitches A by the needlesN or N Needles N now at tuck level, take yarn a, form double stitches SAand cast off floats H and stitches B, while needles N take yarn a toform new elongated loops S on their latches. After needles N and N againpass the two yarn feeds, they are selected to reverse again their yarnformation actions, i.e. to revert to the actions originally described.Thus, after passing each second yarn feed of the machines, the needles,by conventional selecting means, are reversed in their functions toproduce double stitches SA, stitches B and floats H in staggeredrelation throughout the fabric, in the manner shown in FIG. 1.

Because the stitches B are drawn behind the sinker nebs P the floats Hunderlie the elongated loops S and are bound thereby into the fabric(FIG. 1). If desired, the yarn b may be drawn to stitches B on the usualyarn sinking ledge in front of the sinker throats P with appropriaterearrangement of the needle and sinker motions. In such case, floats Hwould overlie, rather than underlie, loops S in the fabric.

Additionally, if desired, alternate sinkers only may be inserted intothe needle circle at the first yarn feed, by appropriate sinkerselection means, to draw yarn a over the nebs of alternate sinkers only.

It is contemplated that, instead of the needle selection means discussedabove for selecting needles N and N modified means may be employedutilizing the auxiliary needle butts N and N In such case, the needles Nand N would be moved independently of each other by means of additionalneedle cams (not shown) arranged at different vertical levels of themachine, and acting upon the auxiliary needle butts N and N.

If desired, in making ladies hosiery, the heel and toe portions may bemade by reciprocatory knitting. In such case, during reciprocatoryknitting, cams C and C at the first yarn feed would be reinserted tooperative position to act upon the needles. No needle butts would enterthe track formed between cams C and C during the forward stroke of theneedle cylinder, but all needles N and N would be drawn down to cast offlevel by cam C During the reverse stroke of the needle cylinder, theieedles would be drawn down by cams C and C in the sual manner. Thereciprocatory knit portions of the fabric would, of course, be a plainknit.

FIG. 5 shows a preferred needle N for carrying out this invention.Needle N is formed with a reduced portion at the front thereof, belowlatch Z and with a second reduced portion 20, formed at the backthereof, below the latch hinge 30. Reduced portion 10 facilitates theformation of the floats H from yarn b, and reduces the strain on theyarn. Reduced portion serves to relieve tension on the loops B aftertheir formation from yarn b.

It is to be understood that the invention described and shown herein issusceptible of various changes and modifications, which may be madewithout departing from the general principles or spirit of the inventiveconcept. Accordingly, it is intended to claim the invention broadly, aswell as specifically, in the appended claims.

Having thus described our invention, we claim:

1. A multi-feed circular knitting machine having a complement of needleswith butts and two successive yarn feeding stations, said machineincluding (a) a run-down stitch cam at each of said yarn feedingstations for lowering needles to yarn cast off level and (b) a secondcam at each of said stations for lowering needles to a level above yarncast off level,

(c) each second cam being spaced from its adjacent stitch cam a distancenot less than the width of a needle butt track corresponding to theWidth of the needle butts.

2. The invention of claim 1 further including needle selection means inadvance of each yarn feeding station to select a group of needles to belowered by the rundown stich cam and to select a good group of needlesto be lowered by the second cam.

3. The invention of claim 1 further including needle selection means inadvance of each yarn feeding station to select needles to be lowered bythe run down stitch cams.

4. The invention of claim 1 further including needle selection means inadvance of each yarn feeding station to select needles to be lowered bythe said second cams.

5. In a multi-feed circular knitting machine having a plurality of latchneedles for knitting run-resistant fabric (a) a first yarn feedingstation including means for feeding yarn to the needles,

(b) a pair of spaced cams at said first station for lowering theneedles, said cams being spaced from each other a distance sufiicient toprovide a needle butt track therebetween,

(c) one of said cams being adapted to lower nonselected needles to yarncast off level and the other of said cams being adapted to lowerselected needles to a level above yarn cast off level,

(d) a second yarn feeding station spaced from the first yarn feed andincluding means for feeding yarn to the needles,

(e) means disposed between the said stations for raising thenon-selected needles to clear yarn from their latches,

(f) means in advance of the second station for dis posing the clearednon-selected needles at tuck level and for disposing the selectedneedles at latch clearing level,

(g) a pair of spaced cams at the second station for lowering theneedles,

(h) one of said latter cams being adapted to lower the non-selectedneedles to yarn cast off level and the other of said latter cams beingadapted to lower the selected needles to tuck level.

6. The invention of claim 5 wherein the machine includes a plurality ofsinkers each having a neb, and further including a sinker cam foradvancing the sinkers into the needle circle at the first station adistance sufficient to permit the needles to draw yarn over the sinkernebs.

7. The invention of claim 6 further including a sinker cam for advancingthe sinkers into the needle circle at the second station a distancesuflicient to permit the nonselected needles to draw yarn over yarnsinking ledges disposed behind the sinker nebs.

8. The invention of claim 5 further including a broken needle detectorand a cam to lower all needles to a depth sufficient to cause yarn onthe needle stems to close the needle latches Without casting ofl 9. Theinvention of claim 7 further including a sinker cam for withdrawing thesinkers from the needle circle after the needles receive yarn at thesecond yarn feeding station.

10. The invention of claim 5 wherein each needle has a reduced portionat the back thereof below the hinge of its latch and a second reducedportion at the front thereof, disposed below the latch.

11. The invention of claim 6 wherein each sinker has a throat and a yarnsinking ledge disposed behind the neb, said ledge being disposed lowerthan the throat.

12. In a circular knitting machine having a plurality of latch needlesand sinkers with nebs and a yarn feed, means for forming spacedelongated yarn loops and intervening knitted stitches course-wise of aknitted fabric comprising (a) needle selection means for disposingselected needles at latch clearing level and the remaining needles attuck level.

(b) a first cam disposed at the yarn feed for lowering the non-selectedneedles to yarn cast off level,

() a second cam disposed at the yarn feed for lowering the selectedneedles to a level above yarn cast off level, whereby said selectedneedles do not cast off (d) said cams being spaced from each other adistance suflicient to provide a needle butt track therebetween, and

(e) a sinker cam adapted to advance the sinkers into the needle circleat the yarn feed.

13. The invention of claim 12 further including (a) means for feedingyarn to the needles,

(b) means for raising the non-selected needles, after feeding yarnthereto, to clear yarn from their latches and (c) means for retainingyarn on the latches of the selected needles.

14. The invention of claim 13 wherein the means for retaining yarn onthe latches of the selected needles comprises a sinker cam forpositioning the sinker nebs within the circle of needles below the yarnon the latches of the selected needles.

15. Means for forming yarn floats in spaced wales of a knitted fabric ona circular knitting machine having at least one yarn feed and aplurality of latch needles comprising (a) means for raising selectedneedles to latch clearing level,

(b) a first cam for lowering the non-selected needles to yarn cast offlevel,

(0) a second cam spaced from the first cam for lowering the selectedneedles to tuck level and (d) means for feeding yarn to the hooks of theselected needles,

(e) said second cam being spaced from the first cam a distancesufficient to cause the non-selected needles to position the yarnagainst the shanks of the selected needles below the latches of saidselected needles to form thereby the yarn floats.

16. A method of knitting run-resistant fabric on a circular knittingmachine having a plurality of latch needles and sinkers having nebscomprising the steps (a) dividing the needles into a first groupdisposed at latch clearing level and a second group disposed at tucklevel,

(b) delivering yarn to the hooks of the needles,

(c) lowering the second group of needles to yarn cast off level,

(d) lowering the first group of needles to a level above yarn cast offlevel, whereby said needles do not cast 01f yarn,

(e) raising the second group of needles to clear yarn from theirlatches,

(f) dividing the needles into the same two groups aforesaid anddisposing the first group at latch clearing level and disposing thesecond group at tuck level,

(g) delivering yarn to the hooks of the second group of needles,

(h) delivering yarn to the stems of the first group of needles, belowthe latches thereof, and then (i) disposing all said needles at tucklevel.

17. The method of claim 16 wherein the sequence of steps is repeated,but with the manipulations of the two groups of needles reversed.

18. The method of claim 16 wherein the needles of the first group eachform elongated yarn loops which are retained on the needle latches andthe needles of the second group each form two successive knittedstitches.

19. The method of claim 18 wherein yarn floats are formed on the stemsof the needles of the first group while said needles retain theelongated yarn loops on their latches.

20. The method of claim 16 further including the step of disposing thesinker nebs within the needle circle to maintain the elongated yarnloops on the latches of the needles of the first group.

21. The method of claim 19 further including the step of positioning thesinker nebs within the circle of needles to maintain the elongated yarnloops on the latches of the needles of the first group.

22. A method of forming yarn floats in spaced wales of aknitted fabricon a circular knitting machine having a plurality of latch needles andat least one yarn feed comprising the steps (a) dividing the needlesinto two groups and disposing one group at latch clearing level anddisposing the other group at tuck level,

(b) delivering yarn to the hooks of the needles dis- .posed at tucklevel,

(0) delivering yarn to the stems of the needles disposed at latchclearing level, below the latches thereof, to form yarn floats,

(d) lowering the needles disposed at tuck level to yarn cast off levelto cast oif of said needles yarn loops disposed below the latchesthereof and then (e) disposing all said needles at tuck level.

References Cited UNITED STATES PATENTS 1,821,848 9/1931 Pons 661082,044,324 6/ 1936 Page 66121 2,249,790 7/1941 Page 66121 2,525,70410/1950 Miller 6642 2,536,478 1/1951 Vitoux 66121 XR 2,073,703 3/ 1937Micks 66108 3,080,740 3/ 1963 Nebel 66108 3,148,518 9/1964 Peel et a1.6642 3,260,072 7/ 1966 Millar et a1 66108 XR FOREIGN PATENTS 594,0085/1959 Italy.

RONALD FELDBAUM, Assistant Examiner.

U.S. Cl. X.R.

